Dependency managers in iOS development are tools that automate the process of adding, updating, and managing third-party libraries and frameworks in Swift and Objective-C projects. These tools simplify the integration of external code, ensuring version compatibility and reducing manual setup errors. The most popular dependency managers for iOS are CocoaPods, Carthage, and Swift Package Manager (SPM). CocoaPods, the oldest and most widely used, integrates directly with Xcode projects and offers a vast library of pods. Carthage provides a more decentralized approach, building frameworks separately from the main project. Swift Package Manager, integrated into Xcode, is Apple's official solution, offering seamless integration with Swift projects. Each manager has its strengths, with developers choosing based on project needs, team preferences, and specific library support. Effective use of dependency managers streamlines development workflows, promotes code reuse, and helps maintain up-to-date, efficient codebases in iOS applications.